Portopulmonary hypertension and serum endothelin levels in hospitalized patients with cirrhosis

Gut Microbiota and Biomarkers of Endothelial Dysfunction in Cirrhosis

Our aim was to study the association of endothelial dysfunction biomarkers with cirrhosis manifestations, bacterial translocation, and gut microbiota taxa. The fecal microbiome was assessed using 16S rRNA gene sequencing. Plasma levels of nitrite, big endothelin-1, asymmetric dimethylarginine (ADMA), presepsin, and claudin were measured as biomarkers of endothelial dysfunction, bacterial translocation, and intestinal barrier dysfunction. An echocardiography with simultaneous determination of blood pressure and heart rate was performed to evaluate hemodynamic parameters. Presepsin, claudin 3, nitrite, and ADMA levels were higher in cirrhosis patients than in controls. Elevated nitrite levels were associated with high levels of presepsin and claudin 3, the development of hemodynamic circulation, hypoalbuminemia, grade 2-3 ascites, overt hepatic encephalopathy, high mean pulmonary artery pressure, increased abundance of Proteobacteria and Erysipelatoclostridium, and decreased abundance of Oscillospiraceae, Subdoligranulum, Rikenellaceae, Acidaminococcaceae, Christensenellaceae, and Anaerovoracaceae. Elevated ADMA levels were associated with higher Child-Pugh scores, lower serum sodium levels, hypoalbuminemia, grade 2-3 ascites, milder esophageal varices, overt hepatic encephalopathy, lower mean pulmonary artery pressure, and low abundance of Erysipelotrichia and Erysipelatoclostridiaceae. High big endothelin-1 levels were associated with high levels of presepsin and sodium, low levels of fibrinogen and cholesterol, hypocoagulation, increased Bilophila and Coprobacillus abundances, and decreased Alloprevotella abundance.

Association between Body Composition and the Risk of Portopulmonary Hypertension Assessed by Computed Tomography in Patients with Liver Cirrhosis

The aim of this study is to investigate the impact of body composition on the risk of portopulmonary hypertension using computed tomography (CT) in patients with liver cirrhosis. We retrospectively included 148 patients with cirrhosis treated at our hospital between March 2012 and December 2020. POPH high-risk was defined as main pulmonary artery diameter (mPA-D) ≥ 29 mm or mPA-D to ascending aorta diameter ratio ≥ 1.0, based on chest CT. Body composition was assessed using CT images of the third lumbar vertebra. The factors associated with POPH high-risk were evaluated using logistic regression and decision tree analyses, respectively. Among the 148 patients, 50% were females, and 31% were found to be high-risk cases on evaluation of chest CT images. Patients with a body mass index (BMI) of ≥25 mg/m2 had a significantly higher prevalence of POPH high-risk than those with a BMI < 25 mg/m2 (47% vs. 25%, p = 0.019). After adjusting for confounding factors, BMI (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.10-1.33), subcutaneous adipose tissue index (OR, 1.02; 95% CI, 1.01-1.03), and visceral adipose tissue index (OR, 1.03; 95% CI, 1.01-1.04) were associated with POPH high-risk, respectively. In the decision tree analysis, the strongest classifier of POPH high-risk was BMI, followed by the skeletal muscle index. Body composition may affect the risk of POPH based on chest CT assessment in patients with cirrhosis. Since the present study lacked data on right heart catheterization, further studies are required to confirm the results of our study.

Greater Muscular Strength Is Associated with a Lower Risk of Pulmonary Dysfunction in Individuals with Non-Alcoholic Fatty Liver Disease

This study investigated the combined effect of handgrip strength (HGS) and non-alcoholic fatty liver disease (NAFLD) on pulmonary function using the Korea National Health and Nutrition Examination Survey (KNHANES) from 2016 to 2018. For the present study, forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), the FEV1/FVC ratio, handgrip strength (HGS) and the hepatic steatosis index (HSI) to estimate NAFLD were obtained from nationwide cross-sectional surveys. For HGS, subjects were divided into higher HGS (upper 50%) and lower HGS (lower 50%). For NAFLD, subjects were divided into the NAFLD cohort (HSI > 36) and the normal cohort (HSI ≤ 36). Of 1651 subjects (men, n = 601), 25.5% of subjects (n = 421) met the HSI > 36. Based on the normal cohort with high HGS, the normal cohort with low HGS showed an increased risk of reduced FVC (OR = 3.062, 95% CI = 2.46−4.83, p < 0.001) and the NAFLD cohort with low HGS showed a further increased risk of reduced FVC (OR = 4.489, 95% CI = 3.43−7.09, p < 0.001). However, the risk of reduced FVC was not significantly increased in NAFLD with high HGS (OR = 1.297, 95% CI = 0.67−2.50, p = 0.436). After adjusted for covariates such as age, sex, smoking, FBG, HDL-C, TG, SBP, DBP, CRP and alcohol consumption, the results remained similar. More importantly, these results were consistent in the obesity-stratified analysis. The current findings of the study suggest that higher muscle strength is associated with a lower risk of reduced pulmonary function in individuals with NAFLD.

Ambrisentan in portopulmonary hypertension: A multicenter, open-label trial

BACKGROUND

Ambrisentan has shown effectiveness in the treatment of Group 1 pulmonary arterial hypertension (PAH). Although portopulmonary hypertension (PoPH) is a subset of Group 1 PAH, few clinical trials have been testing PAH therapies in patients with PoPH. The objective of this study is to evaluate the efficacy and safety of ambrisentan in PoPH.

METHODS

This study is a prospective, multicenter, open-label trial in which treatment-naive patients with PoPH with Child-Pugh class A/B were administered with ambrisentan for 24 weeks, followed by a long-term extension (24-28 weeks). The primary end-points were change in pulmonary vascular resistance (PVR) and 6-minutes walk distance (6MWD) at 24 weeks, whereas secondary end-points included safety, World Health Organization (WHO) functional class (FC) and echocardiographic assessments.

RESULTS

Of the 31 patients, 23 finished 24 weeks of ambrisentan therapy and 19 finished the extension. PVR decreased significantly (mean ± SD) (7.1 ± 5 vs 3.8 ± 1.8 Wood units, p < 0.001), whereas 6MWD remained unchanged (314 ± 94 vs 336 ± 108 m). Other hemodynamic parameters such as right atrial pressure (13 ± 8 vs 9 ± 4 mm Hg, p < 0.05), mean pulmonary arterial pressure (46 ± 13 vs. 38 ± 8 mm Hg, p < 0.01), cardiac index (2.6 ± 0.6 vs. 3.5 ± 0.7 liter/min/m², p < 0.001) showed improvement, whereas pulmonary capillary wedge pressure remained unchanged. Of the 22 patients with WHO FC assessments at baseline and 24 weeks, WHO FC improved significantly (p = 0.005). Most frequent drug-related adverse events were edema (38.7%) and headache (22.5%). One episode of leg edema resulted into the permanent discontinuation of ambrisentan.

CONCLUSIONS

Ambrisentan monotherapy in PoPH improves hemodynamics and FC at 24 weeks; however, it did not show any improvement in 6MWD. These preliminary outcomes should be interpreted with caution (Clinicaltrials.Gov:NCT01224210).

Effective shunt closure for pulmonary hypertension and liver dysfunction in congenital portosystemic venous shunt

OBJECTIVE

Congenital portosystemic venous shunt (CPSVS) is a rare vascular malformation with a high risk of mortality from pulmonary arterial hypertension (PAH), but the treatment outcome of CPSVS closure remains elusive. Our aim was to investigate the clinical features and establish the optimal management of CPSVS with or without PAH.

METHODS

Twenty-four patients with CPSVS treated in Kyushu University Hospital between 1990 and 2015 were enrolled in this study. The patients were divided into a PAH group (n = 9) and a non-PAH group (n = 15). Clinical characteristics and outcomes were evaluated.

RESULTS

The first manifestation of CPSVS at diagnosis (28.5 [1-216] months) was hypergalactosemia in 13 (54%) or PAH in six (25%) patients. PAH was the cause of all three deaths. The PAH group had higher levels of serum total bile acid, manganese, and total bilirubin, along with higher pulmonary vascular resistance index (PVRI) than the non-PAH group (7.2 [5.1-38.1] vs 1.2 [0.5-3.3] unit/m² , P < 0.001). Five of nine PAH patients underwent CPSVS closure at a median of 38 months (range 21-118) after PAH diagnosis. Pulmonary artery pressure improved after CPSVS closure with PAH-specific therapy, but normal range was not achieved. CPSVS closure improved the hepatic synthetic function of four PAH patients. Eigh-t of 15 non-PAH patients who received CPSVS closure did not develop PAH for a median of 34.5 months (range 6-164) after the procedure.

CONCLUSIONS

CPSVS closure with PAH-specific therapy successfully controlled PAH. Early CPSVS closure may prevent the occurrence and progression of PAH with CPSVS.

What's new in the treatment of portopulmonary hypertension?

Portopulmonary hypertension (POPH) is a complication of portal hypertension characterized by pulmonary vasoconstriction and vascular remodeling that can lead to right heart failure and death. Differentiation of POPH from other causes of pulmonary hypertension, such as volume overload or a hyperdynamic high flow state, is critical because a diagnosis of POPH has significant implications for liver transplant risk stratification, Model for End Stage Liver Disease exception points, and the use of pulmonary arterial hypertension-(PAH) specific therapy. Currently, there are 12 approved medications for the treatment of PAH in the US, and three of these were approved in 2013. This review will discuss the diagnosis, evaluation and management of POPH and the role of recently approved PAH therapies in the treatment of POPH.

Correlation between Saliva and Plasma Levels of Endothelin Isoforms ET-1, ET-2, and ET-3

Although saliva endothelins are emerging as valuable noninvasive cardiovascular biomarkers, reports on the relationship between isoforms in saliva and plasma remain scarce. We measured endothelins in concurrent saliva and plasma samples (n = 30 males; age 18–63) by HPLC-fluorescence. Results revealed statistically significant positive correlations among all isoforms between saliva and plasma: big endothelin-1 (BET-1, 0.55 ± 0.27 versus 3.35 ± 1.28 pmol/mL; r = 0.38, p = 0.041), endothelin-1 (ET-1, 0.52 ± 0.21 versus 3.45 ± 1.28 pmol/mL; r = 0.53, p = 0.003), endothelin-2 (ET-2, 0.21 ± 0.07 versus 1.63 ± 0.66 pmol/mL; r = 0.51, p = 0.004), and endothelin-3 (ET-3, 0.39 ± 0.19 versus 2.32 ± 1.44 pmol/mL; r = 0.75, p < 0.001). Correlations of BET-1, ET-1, and ET-3 within each compartment were positive in both plasma (p < 0.05) and saliva (p ≤ 0.1), whereas ET-2 was not significantly correlated with other isoforms in either plasma or saliva. For all isoforms, concentrations varied on average fivefold between individuals (90th/10th percentiles); individuals with high plasma endothelin levels generally had high saliva endothelin levels. Our results reveal that salivary ET isoform profiles portray the plasmatic profiles and support the view of coordinated regulation of ET-1 and ET-3, but distinct regulatory pathways for ET-2.

Pathological changes in pulmonary circulation in carbon tetrachloride (CCl4)-induced cirrhotic mice

RATIONALE

Lack of an experimental model of portopulmonary hypertension (POPH) has been a major obstacle in understanding of pathophysiological mechanisms underlying the disease.

OBJECTIVE

We investigated the effects of CCl4-mediated cirrhosis on the pulmonary vasculature, as an initial step towards an improved understanding of POPH.

METHODS AND RESULTS

Male C57BL/6 mice received intraperitoneal injection of either sterile olive oil or CCl4 3 times/week for 12 weeks. Cirrhosis and portal hypertension were confirmed by evidence of bridging fibrosis and nodule formation in CCl4-treated liver determined by trichrome/picrosirius red staining and an increase in spleen weight/body weight ratio, respectively. Staining for the oxidative stress marker, 4-hydroxynonenal (4-HNE), was strong in the liver but was absent in the lung, suggesting that CCl4 did not directly induce oxidative injury in the lung. Pulmonary acceleration time (PAT) and the ratio of PAT/pulmonary ejection time (PET) measured by echocardiography were significantly decreased in cirrhotic mice. Increase in right ventricle (RV) weight/body weight as well as in the weight ratio of RV/(left ventricle + septum) further demonstrated the presence of pathological changes in the pulmonary circulation in these mice. Histological examination revealed that lungs of cirrhotic mice have excessive accumulation of perivascular collagen and thickening of the media of the pulmonary artery.

CONCLUSION

Collectively, our data demonstrate that chronic CCl4 treatment induces pathological changes in pulmonary circulation in cirrhotic mice. We propose that this murine cirrhotic model provides an exceptional tool for future studies of the molecular mechanisms mediating pulmonary vascular diseases associated with cirrhosis and for evaluation of novel therapeutic interventions.

Ultrasonic diagnosis and vasoactive substances examination in patients with cirrhosis

OBJECTIVE

To investigate hemodynamic change of patients with cirrhosis by using Color Doppler ultrasound technique and to explore the significance of change in the content of vasoactive substances-plasma endothelin-1 (ET-1) and calcitonin gene-related peptide (CGRP).

METHODS

A total of 178 cases with cirrhosis were regarded as study groups, and were divided into three degrees: A, B and C according to child-pugh and meanwhile 60 cases were regarded as normal control group. Portal vein and splenic vein of patients were explored by adopting Color Doppler ultrasound technique, related indexes were recorded and the blood flow as well as their ration in the two groups was calculated. Radio immunoassay was adopted to detect the content of plasma ET-1 and CGRP in both study group and contrast group.

RESULTS

Compared with the healthy cases in the contrast group, there was abnormal hemodynamics in the system of portal vein of patients with cirrhosis and the content of plasma ET-1 and CGRP was increased obviously. In the Child-Pugh liver function grades, the content of ET-1 and CGRP was increased as the degree of cirrhosis became more and more serious. There was no significant difference in the comparison between those without ascites and those in contrast group (P>0.05), the content of plasma ET-1 and CGRP in patients without ascites was increased remarkably. Besides, there was positive correlation between the content of plasma ET-1 and CGRP and Dpv, Dsv and Qsv.

CONCLUSION

Detection of abnormal hemodynamics of portal vein and splenic vein by Color Doppler ultrasound technique can be one of the means for diagnosis of hypertension. Plasma ET-1 and CGRP of patients with cirrhosis reflect the serious degree of the damage in live function and play an important role in the formation and development of portal hypertension.

Pulmonary vascular complications in portal hypertension and liver disease: a concise review

Chronic liver disease and/or portal hypertension may be associated with one of the two pulmonary vascular complications: portopulmonary hypertension and hepatopulmonary syndrome. These pulmonary vascular disorders are notoriously underdiagnosed; however, they have a substantial negative impact on survival and require special attention in order to understand their diagnostic approach and to select the best therapeutic options. Portopulmonary hypertension results from excessive vasoconstriction, vascular remodeling, and proliferative and thrombotic events within the pulmonary circulation that lead to progressive right ventricular failure and ultimately to death. On the other hand, abnormal intrapulmonary vascular dilations, profound hypoxemia, and a wide alveolar-arterial gradient are the hallmarks of the hepatopulmonary syndrome, resulting in difficult-to-treat hypoxemia. The aim of this review is to summarize the latest pathophysiologic concepts, diagnostic approach, therapy, and prognosis of portopulmonary hypertension and hepatopulmonary syndrome, as well as to discuss the role of liver transplantation as a definitive therapy in selected patients with these conditions.